In a large skillet, cook the sausage until browned; drain well.
In a 5- to 6-quart slow cooker, place squash, potatoes, fennel, onion, garlic, beans and sage. Top with sausage. Pour broth and wine over all.
Cover and cook on Low for 8 to 10 hours or on High for 4 to 5 hours. Stir in kale (or spinach). Cover and cook 5 minutes more.